外膜蛋白OmpU对副溶血弧菌耐药性的影响

Effect of OmpU on Antibiotics Resistance of Vibrio parahaemolyticus

摘要:

为了研究外膜蛋白OmpU对副溶血弧菌耐药性的影响，作者构建了副溶血弧菌中高丰度外膜蛋白OmpU缺失的突变株ΔompU。通过最小抑菌浓度（MIC）检测发现ΔompU对12种抗生素的耐药性发生变化，其中对氨苄青霉素的耐药性增加幅度最高。定量反转录PCR显示，在氨苄青霉素刺激下，野生型副溶血弧菌与ΔompU中肽聚糖合成基因转录水平普遍下调，而编码β内酰胺酶的基因VP_RS17515在野生型中转录水平高于/i>ΔompU。结果表明，副溶血弧菌通过表达β内酰胺酶并降低肽聚糖合成速度的方式应对氨苄青霉素刺激，而OmpU通过改变细胞膜通透性来影响氨苄青霉素的渗入。

Abstract:

For understanding the effect of OmpU on antibiotics resistance of Vibrio parahaemolyticus, a deletion mutant strain of the highly abundant outer membrane protein(OmpU) in Vibrio parahaemolyticus, designated as ΔompU, was constructed in this study. Minimum inhibitory concentration (MIC) assay revealed altered antibiotic resistances of ΔompU to 12 antibiotics, with the highest increase observed in resistance to ampicillin. Quantitative reverse transcription PCR showed a general downregulation in the transcription level of peptidoglycan synthesis genes in both wild-type (WT) and ΔompU cells under ampicillin stimulation. However, the gene VP_RS17515 encoding β-lactamase exhibited the higher transcription level in WT strains than ΔompU. The results suggest that V. parahaemolyticus responds to ampicillin through expressing β-lactamase and reducing peptidoglycan synthesis rates, while OmpU changes the cell membrane permeability to affect the penetration of ampicillin.